Children are being put in danger because the family court service is facing an "acute situation of crisis", according to Sir Mark Potter, the former president of the family division and head of family justice for England and Wales.

The combination of a lack of funding and an overwhelming increase in child protection cases over the past two years has led to children waiting for up to two years for courts to come to a decision, despite living in environments of domestic violence and high parental conflict.

"Delays are causing children to be left for a considerable proportion of their early lives in atmospheres of violence, high emotion and parental dispute which, if prolonged, is bound to interfere with their long-term development and give rise to problems in adolescence and later life," said Potter, in his first interview since leaving office .

These delays, Potter added, were likely to increase further as a growing number of parents are forced to represent themselves in court because of an exodus of experienced professionals from the legal aid system. Parents who put their cases to the court without professional advice and support can extend a court case to twice its usual length.

Potter admitted he felt like a "deserter" for leaving his post when the future of the system was under such acute threat.

Cuts to already "inadequate" legal aid funding, combined with a sharp growth in cases over the past two years and a crisis in the funding of Cafcass, the court welfare service, had put the system under intolerable strain, said Potter, who was the most senior family judge in England and Wales until he retired last April. In an interview at his South Kensington home, Potter said: "I don't want to be seen as a merchant of doom, but the system is becoming overwhelmed in the face of an increasing workload and inadequate resources.

"I am a pessimist as to the prospects of immediate improvement or to the likelihood of any reduction to the delays inherent in our complicated system," he added. "It is really very sad to have to be saying this sort of thing at the moment of my exit from the field. For years, I sought to preach the message to all the idealists and very overworked people in the family justice system that the problem of resources and its effects upon the family justice system mean there are tricky times ahead but that we can do it together.

"But now, when that promise is going to be tested in the face of further cuts threatened as a result of government difficulty, I shall not be there to share the pain. I feel like a deserter to be leaving at this acute situation of crisis. But with the current pressures upon the system and the amount of administrative work involved, five years is enough for the head of a division to serve before importing the benefits of a fresh mind."

Potter, who was a judge for 22 years and sat in the court of appeal, introduced a number of procedures to simplify and accelerate the court process. He took up the post of head of family law in England and Wales in 2005.

Known as a restrained figure during his tenure, Potter said he felt able to speak more freely now he had left his post.

Warning that access to justice for ordinary families was being undermined, he spoke of "advice deserts" around the country, areas in which local family law firms had been forced to close because of poor remuneration and uncertainty about the future of legal aid provision. "There are substantial numbers of advice deserts across England and Wales where family law solicitors have dropped out of doing publicly funded work," he said.

According to figures from Resolution, the family solicitors' organisation, the number of family legal aid practices in England and Wales fell from 4,500 in 2000 to 2,800 in 2006.

"It's a frightening fact but in many areas of the country, there is just a single family law firm in a 60-mile radius," he said. "Where parents are in conflict over care proceedings, it becomes a race between the mother, the father and the children's guardian, who gets to that lawyer first. It's unlikely to be the harassed mother, so where does she go for advice and support?" he asked. "Probably 80% of the people the family law service deal with lack the financial means to pay to be represented in court. Most have little education or understanding of court procedures or, by very reason of their emotional states, should not be acting in person.

"Trying to achieve the least worst outcome for the children of these parents is an intense exercise in guidance and support on the part of experienced, specialist lawyers. And yet that support isn't available for an increasing number of families."

This, he added, is already a real problem across England and Wales. "Yet it's likely to get worse; there isn't going to be an increase in legal aid and it's no longer economic for these lawyers to put in the necessary hours. Apart from a few saints, this drives out the conscientious firms and leaves only those prepared to do the work in a superficial way," he said.

Potter also said it was "inevitable" that children would suffer from the recent opening up of the courts to media scrutiny.

"I reluctantly supported the change to more open courts because it had got to the point of allegations being made of secret justice and injustice taking place behind closed doors.

"I was confident these allegations would be dispelled by the attendance of the press at the proceedings and I am happy to see this has largely been the case," he said.

"But the fact is that if you have a newspaper report, even one subject to anonymity, most cases are tried in a local county court and of course those in the local area get to know about it. There's no denying the fact that children are bound to be adversely affected when the case becomes the subject of local gossip or bullying at school," he said. "This is a sad spin-off that has unfortunately to be recognised in the interests of open justice."